Difference between revisions of "Analysis DParticleCombo"

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(→‎Comparing Particles Between Combos (and/or Reactions))
 
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* Located in sim-recon/src/libraries/ANALYSIS/
 
* Located in sim-recon/src/libraries/ANALYSIS/
 
* '''DParticleComboStep''': Contains a possible combination of particles for an interaction or decay step in a reaction.
 
* '''DParticleComboStep''': Contains a possible combination of particles for an interaction or decay step in a reaction.
−
** <span style="color:#0000FF">DParticleComboStep</span> nearly mirrors <span style="color:#0000FF">DReactionStep</span>, containing particles instead of particle types, but in the same order.   
+
** <span style="color:#0000FF">DParticleComboStep</span> nearly mirrors <span style="color:#0000FF">DReactionStep</span>, containing particles instead of PIDs, but in the same order.   
−
* '''DParticleCombo''': Contains a possible combination of <span style="color:#0000FF">DParticleComboStep</span> objects for a reaction, along with a pointers to the corresponding <span style="color:#0000FF">DReaction</span> and (optional) <span style="color:#0000FF">DKinFitResults</span>.  
+
* '''DParticleCombo''': Contains a possible combination of <span style="color:#0000FF">DParticleComboStep</span> objects for a reaction, along with a pointer to the corresponding <span style="color:#0000FF">DKinFitResults</span>.  
−
** <span style="color:#0000FF">DParticleCombo</span> nearly mirrors <span style="color:#0000FF">DReaction</span>, containing <span style="color:#0000FF">DParticleComboStep</span> objects instead of <span style="color:#0000FF">DReactionStep</span> objects, but in the same order.  
+
** <span style="color:#0000FF">DParticleCombo</span> nearly mirrors <span style="color:#0000FF">DReaction</span>, containing <span style="color:#0000FF">DParticleComboStep</span> objects instead of <span style="color:#0000FF">DReactionStep</span> objects, but in the same order.
  
−
=== Particles ===
+
== Creation ==
 +
* Any detected +/-/neutral particle can be any of the desired +/-/neutral particles in the <span style="color:#0000FF">DReaction</span>: find all possible combinations.
 +
** This is regardless of PID: Only loose PID cuts are applied by default.
 +
** Note: If a <span style="color:#0000FF">DChargedTrack</span> has hypotheses with different charges, tested as both + and -.
 +
*** This can happen if the track reconstruction flips the sign of one of the hypotheses, but not the others.
 +
* There can be (very, very) many <span style="color:#0000FF">DParticleCombo</span> objects for a single event: user should apply cuts to remove the (combinatoric) background combinations.
  
−
* Particle data is contained in either <span style="color:#0000FF">DChargedTrackHypothesis</span>, <span style="color:#0000FF">DNeutralParticleHypothesis</span>, <span style="color:#0000FF">DBeamPhoton</span>, or <span style="color:#0000FF">DKinematicData</span> (for reconstructed missing or decaying particles) objects.
+
== Particles ==
 +
 
 +
* Particle data is contained in either <span style="color:#0000FF">DChargedTrackHypothesis</span>, <span style="color:#0000FF">DNeutralParticleHypothesis</span>, <span style="color:#0000FF">DBeamPhoton</span>, <span style="color:#0000FF">DMCThrown</span>, or <span style="color:#0000FF">DKinematicData</span> (for reconstructed missing or decaying particles) objects.
 
** However, all of these objects are stored in <span style="color:#0000FF">DParticleComboStep</span> as pointers to <span style="color:#0000FF">DKinematicData</span>.  If you want the <span style="color:#0000FF">DBeamPhoton</span>, etc. objects, you need to cast them back that type.   
 
** However, all of these objects are stored in <span style="color:#0000FF">DParticleComboStep</span> as pointers to <span style="color:#0000FF">DKinematicData</span>.  If you want the <span style="color:#0000FF">DBeamPhoton</span>, etc. objects, you need to cast them back that type.   
  
 
* Both the measured data and the kinematic fit data are accessible from these classes.
 
* Both the measured data and the kinematic fit data are accessible from these classes.
−
** In <span style="color:#0000FF">DParticleCombo</span> objects grabbed from the default (no tag) factory, the kinematic data is stored in the "default" members (<span style="color:#008000">dFinalParticles</span> and <span style="color:#008000">dInitialParticle</span>) and the measured data is stored in the "measured" members (<span style="color:#008000">dFinalParticles_Measured</span> and <span style="color:#008000">dInitialParticle_Measured</span>).  
+
** The measured data can be accessed by calling the <span style="color:#008000">Get_InitialParticle_Measured</span> and <span style="color:#008000">Get_FinalParticle_Measured</span>(<span style="color:#0000FF">size_t</span>) functions on a particle combination.
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** In <span style="color:#0000FF">DParticleCombo</span> objects grabbed from the "PreKinFit" tag factory, the measured data is stored in the both the "default" and the "measured" members.
+
** The the <span style="color:#008000">Get_InitialParticle</span> and <span style="color:#008000">Get_FinalParticle</span>(<span style="color:#0000FF">size_t</span>) functions return the Measured/Kinfit data.
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** To access these particles, call <span style="color:#0000FF">DParticleComboStep</span> functions such as: <span style="color:#008000">Get_InitialParticle</span>(<span style="color:#0000FF">size_t</span>), <span style="color:#008000">Get_InitialParticle_Measured</span>(<span style="color:#0000FF">size_t</span>), <span style="color:#008000">Get_FinalParticle</span>(<span style="color:#0000FF">size_t</span>), <span style="color:#008000">Get_FinalParticle_Measured</span>(<span style="color:#0000FF">size_t</span>)
+
  
 
* The source objects (<span style="color:#0000FF">DChargedTrack</span> and <span style="color:#0000FF">DNeutralShower</span>) are accessible by calling <span style="color:#0000FF">DParticleComboStep</span>::<span style="color:#008000">Get_FinalParticle_SourceObject</span>(<span style="color:#0000FF">size_t</span>).  
 
* The source objects (<span style="color:#0000FF">DChargedTrack</span> and <span style="color:#0000FF">DNeutralShower</span>) are accessible by calling <span style="color:#0000FF">DParticleComboStep</span>::<span style="color:#008000">Get_FinalParticle_SourceObject</span>(<span style="color:#0000FF">size_t</span>).  
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** The source and measured pointers will be NULL, and the "default" pointers will be NULL unless they are constrained by the kinematic fit (e.g. resonances are not constrained, but a &Lambda; or a missing recoil proton will be).
 
** The source and measured pointers will be NULL, and the "default" pointers will be NULL unless they are constrained by the kinematic fit (e.g. resonances are not constrained, but a &Lambda; or a missing recoil proton will be).
  
−
=== Source Code ===
+
== Comparing Particles Between Combos (and/or Reactions) ==
−
* C++ code of class members (methods aren't shown):  
+
* To know whether a particle in one <span style="color:#0000FF">DParticleCombo</span> is the same physical track/shower as a particle in another <span style="color:#0000FF">DParticleCombo</span>, you cannot directly compare the particle-object pointers. This is because the specific instances of these particles are likely unique to their combinations.
−
<syntaxhighlight>
+
* Instead, you need to compare source objects (see above section).
−
class DParticleComboStep
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−
{
+
−
  private:
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−
    // BLUEPRINT:
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    const DParticleComboBlueprintStep* dParticleComboBlueprintStep; //contains PIDs, source objects
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−
 
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    // INITIAL PARTICLES:
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    const DKinematicData* dInitialParticle; //if is null: decaying or beam particle not yet set!
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    const DKinematicData* dInitialParticle_Measured; //if is null: decaying or beam particle not yet set!
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    const DKinematicData* dTargetParticle; //NULL for no target
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−
 
+
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    // FINAL PARTICLES:
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    deque<const DKinematicData*> dFinalParticles; //if particle is null: missing or decaying! //these are DChargedTrackHypothesis or DNeutralParticleHypothesis objects if detected
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    deque<const DKinematicData*> dFinalParticles_Measured; //if particle is null: missing or decaying! //these are DChargedTrackHypothesis or DNeutralParticleHypothesis objects if detected
+
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};
+
−
</syntaxhighlight>
+
−
 
+
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<syntaxhighlight>
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−
class DParticleCombo : public JObject
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−
{
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  private:
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    const DReaction* dReaction;
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    const DKinFitResults* dKinFitResults;
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    deque<const DParticleComboStep*> dParticleComboSteps;
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−
};
+
−
</syntaxhighlight>
+

Latest revision as of 06:48, 3 November 2017

Summary

  • Located in sim-recon/src/libraries/ANALYSIS/
  • DParticleComboStep: Contains a possible combination of particles for an interaction or decay step in a reaction.
    • DParticleComboStep nearly mirrors DReactionStep, containing particles instead of PIDs, but in the same order.
  • DParticleCombo: Contains a possible combination of DParticleComboStep objects for a reaction, along with a pointer to the corresponding DKinFitResults.
    • DParticleCombo nearly mirrors DReaction, containing DParticleComboStep objects instead of DReactionStep objects, but in the same order.

Creation

  • Any detected +/-/neutral particle can be any of the desired +/-/neutral particles in the DReaction: find all possible combinations.
    • This is regardless of PID: Only loose PID cuts are applied by default.
    • Note: If a DChargedTrack has hypotheses with different charges, tested as both + and -.
      • This can happen if the track reconstruction flips the sign of one of the hypotheses, but not the others.
  • There can be (very, very) many DParticleCombo objects for a single event: user should apply cuts to remove the (combinatoric) background combinations.

Particles

  • Particle data is contained in either DChargedTrackHypothesis, DNeutralParticleHypothesis, DBeamPhoton, DMCThrown, or DKinematicData (for reconstructed missing or decaying particles) objects.
    • However, all of these objects are stored in DParticleComboStep as pointers to DKinematicData. If you want the DBeamPhoton, etc. objects, you need to cast them back that type.
  • Both the measured data and the kinematic fit data are accessible from these classes.
    • The measured data can be accessed by calling the Get_InitialParticle_Measured and Get_FinalParticle_Measured(size_t) functions on a particle combination.
    • The the Get_InitialParticle and Get_FinalParticle(size_t) functions return the Measured/Kinfit data.
  • The source objects (DChargedTrack and DNeutralShower) are accessible by calling DParticleComboStep::Get_FinalParticle_SourceObject(size_t).
    • These objects are returned as type const JObject*, and may be cast to either DChargedTrack or DNeutralShower as appropriate.
  • Particles that are missing or are decaying may have NULL pointers stored for the objects.
    • The source and measured pointers will be NULL, and the "default" pointers will be NULL unless they are constrained by the kinematic fit (e.g. resonances are not constrained, but a Λ or a missing recoil proton will be).

Comparing Particles Between Combos (and/or Reactions)

  • To know whether a particle in one DParticleCombo is the same physical track/shower as a particle in another DParticleCombo, you cannot directly compare the particle-object pointers. This is because the specific instances of these particles are likely unique to their combinations.
  • Instead, you need to compare source objects (see above section).
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